Determination of ammonia in air and aqueous samples with a gas-sensitive semiconductor capacitor
1984 (English)In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 164, 127-138 p.Article in journal (Refereed) Published
The properties of a new type of ammonia gas-sensitive semiconductor capacitor are described. The sensor is based on a palladium MOS field-effect capacitor with a thin layer (3 nm) of iridium surrounding the palladium gate. The lower limit of detection for ammonia in air is 1 ppm (0.59 mg kg−1). The analytical characteristics and temperature-dependence of the sensor in measurements of ammonia in air are evaluated. Ammonia in aqueous solutions is determined by the use of a continuous flow system utilizing a gaspermeable membrane in combination with the sensor. The calibration plot of the voltage drop of the capacitor vs. ammonia concentration in 150-μl samples is linear in the concentration range 0.2 × 10−6–5 × 10−5 M. Ammonia is determined in rain and river water as well as in whole blood and blood serum; 15 samples per hour can be assayed. Analytical recovery studies and the selectivity properties of the system are described and discussed. Finally, the properties of the flow-through system in continuous monitoring are described.
Place, publisher, year, edition, pages
Elsevier, 1984. Vol. 164, 127-138 p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-88167DOI: 10.1016/S0003-2670(00)85624-XISI: A1984ABC2700012OAI: oai:DiVA.org:liu-88167DiVA: diva2:601825